In pursuit of higher engine efficiencies, higher turbine inlet temperatures have been relied upon to boost overall engine performance. This can result in gas path temperatures that may exceed melting points of turbine component materials. To address this issue, dedicated cooling air is extracted from a compressor section and is used to cool the gas path components in the turbine, such as rotating blades and stator vanes for example.
One method of cooling turbine airfoils utilizes internal cooling passages. Typically, film cooling holes and significant volumes of cooling air are required to provide the needed amount of cooling. One area that is difficult to effectively cool is a tip of the airfoil. Tip shelves and squealer pockets have been incorporated into the tip of the blade to improve cooling but have not always been capable of effectively cooling a leading edge portion of the tip.